TV is a pretty important technique in every person’s home. Like any other complex device, it may for some reason stop working. Breakdowns can be different, but the most common situation is when the TV screen suddenly starts to blink violently or simply turns off while watching. Of course, this can cause great concern to the owner of the equipment, but you should not particularly worry. To begin with, it is important to establish the main reason why the image on the TV disappears, and the sound works.
What situations can be?
The cause of problems with the image and sound can be many. The most common problems faced by many owners of smart TVs include the situation when the image is lost on the LCD TV and there is sound. Additionally, the problem may be expressed in the following:
- the television makes a sound, but the picture itself is missing;
- I can’t switch the channel normally due to the black screen;
- backlight does not work;
- the technique leads to a strong distortion of the image, changes its size, leads to the need to change the image format;
- the brightness of the screen greatly deteriorates, the colors become too dull;
- The image broadcast disappears from time to time, and the TV screen turns off.
Before undertaking the repair of your device, it is important to accurately determine the cause of the malfunction and consider the course of your further actions.
What problems can arise?
Why does the picture disappear on the TV? The most common reason that the image on the TV starts to fade and the sound disappears is a hardware failure. Problems with the functioning of the power supply or the color block, a burnt inverter, a broken matrix and a capacitor - all this in the majority leads to the following problems:
- stop showing all shows;
- the color of the picture changes to green or black and white;
- the image changes its position, flips, changes the format;
- other types of problems may also occur when the video itself is absent, but the sound continues to function normally.
The TV has lost the image - what to do? To get rid of such a problem, you should seek help from a private foreman working in the repair center, or carry out an independent search for the problem and its solution.
Test cable
If the sound from the device comes at a normal volume of the audio track, but the TV screen remains dark, the main solution will be to test the cable that transmits the image:
- antenna
- HDMI 3;
- from cable provider;
- checking the connection of the Internet network (this must be done when the TV is equipped with a digital set-top box).
To carry out such a check, you will have to use the special Moinfo utility. It was created specifically to identify the main problems with the functioning of the device when transmitting video signals and sounds. If the application was able to determine malfunctions in the operation of the device, then the owner should carefully inspect the cable contacts for any possible damage.
Matrix issues
Probably the most common reason why the image disappears from the TV screen or a strong change occurs is the breakdown of the matrix. If the matrix is damaged, the following symptoms can be observed:
- jumping picture;
- the screen starts to show only half of the afterimage;
- streaks of different colors or one (pink, white, yellow) begin to go across the screen.
Most often, the matrix breaks under the influence of factors from the outside, for example, with the accidental ingress of water, falling, impact of strong power. In this case, the screen cannot be repaired, you will have to purchase a new matrix (or even buy a new TV).
If problems with such a detail arose without specific reasons, for example, the picture suddenly began to become cloudy or doubled, then this condition can be corrected in the technical service. It replaces the old module with a new, well-functioning one.
Also, the matrix of the TV can be replaced independently at home, but it will be very difficult for a lay person in this field to make a replacement with their own hands. The first problems will arise already in the process of preparing for the repair: to find the right matrix model for a particular TV is not easy, it will have to be ordered through the official service centers of the city. Otherwise, there is a high risk of acquiring a fake, which will only adversely affect the condition and functioning of the equipment.
Capacitors burnt in the device
Problems with the operation of capacitors in LCD TVs appear due to strong power surges. External signs of failure can be as follows: the image on the TV suddenly disappears and the screen itself goes off, the signal stops immediately after turning on the device or after a short period of time, the picture doubles or loses its brightness - darkening, dullness. After disassembling the TV on the board, you can find a blown up or exploded capacitor, as well as a blown fuse.
It is important to pay special attention to the fact that after recharging the power supply is the first to fail. Diagnostic measures should be carried out in the same way as in other situations. Repair of the TV should be carried out by an experienced professional who will prevent the complication of the situation and not break it completely.
Matrix loopback issues
The main signs by which it can be understood that it is the loop of the matrix that is broken, the following manifestations are considered:
- from time to time the image disappears on the TV screen;
- the device does not show the image normally - interference occurs, the monitor strongly ruffles;
- you may notice a distortion of the picture: a large number of stripes appears on the screen or the ghosting of the picture in geometric order.
After turning to the wizard for help, he can suggest the following solutions to the problem:
- loop repair;
- purchase of a new part.
The first method is considered time-consuming and inappropriate, since it will be much easier to dismantle the broken spare part and change it to a new one than to try to fix it. You should not try to cope with such a task yourself.
Backlight problems
Another fairly common reason for the extinction of the image on the screen is the poor operation of the backlight. In LV devices, the LEDs in the LED backlight stop functioning normally. It will be quite simple to identify such a problem - the image blinks strongly, a characteristic ripple appears on it, but the main problem is the malfunction of highlighting of the polymer liquid crystal layer.
To cope with such a problem and repair the backlight with your own efforts at home is almost impossible due to the lack of all the necessary details. It is too long and expensive to order them from an official supplier, and such spare parts are simply not supplied to the radio market. For this reason, the best solution would be to send the broken equipment to a certified service center with experienced craftsmen.
Blown inverter
It is simply impossible to describe all the causes of a failure of the voltage inverter in the TV. The main symptoms of a breakdown include the following phenomena:
- the picture flickers a lot, distortion appears;
- when you turn on the TV, the image disappears;
- the video sequence either does not appear on the monitor for a long time or is completely absent;
- the TV display after turning on becomes dull and turns off after a short period of time;
- sound is present, but there are ripples or stripes on the screen;
- The broadcast picture is very blurry, dark, which does not allow to determine what is happening on the screen.
The inverter is not only responsible for the transfer of energy to the backlight, but also:
- converts 12 volts DC to high voltage AC;
- restores the lamp output current to an acceptable level;
- restores the brightness of the picture, when necessary increases or decreases it;
- matches the output stage of the inverter and the input resistance of the lamps;
- prevents circuit of electronic boards, prevents them from overloading too much.
Only someone who knows how to use a soldering iron and a multimeter, and also has at least basic school knowledge in electronics and physics, can fix a broken inverter on their own. It is difficult to accurately answer the question of where the burnout of parts most often occurs, since a problem can occur anywhere: board controllers, lamps, and also transformers.
Power supply
If the TV still has sound, but there is no picture, but the monitor blinks constantly, its color is dull, and the image is not displayed correctly or appears very late, then the problem is most likely with the power supply.
Trying to repair the power supply yourself at home without sufficient knowledge in electronics and physics is prohibited, as this can only worsen the situation and lead to dangerous consequences. It is best to entrust this matter to a professional who will quickly determine the breakdown and repair it.